针对RSA-CRT数字签名的光故障攻击研究

通过研究密码芯片SRAM存储单元构造,利用激光改变进行运算的SRAM存储单元的逻辑状态,分析光注入对SRAM存储单元的影响。以Montgomery乘的 RSA－CRT数字签名算法为攻击对象,分析其算法的实现过程和故障注入机理。针对密码芯片实现的8位RSA－CRT签名算法,使用半导体激光作为注入光源,搭建光注入实验平台,在计算Sq时刻进行故障注入,从而得到故障签名,通过分析故障签名与N的关系,成功的获得了大素数q,验证了光故障攻击的有效性。     

GPR target detection using a neural network classifier designed by a multi-objective genetic algorithm

Ground Penetrating Radar (GPR) is an electromagnetic sensing technology employed for localization of underground utilities, pipes, and other types of objects. The radargrams typically obtained have a high dimensionality, containing a number of signatures with hyperbolic pattern shapes, and can be processed to retrieve information about the target’s locations, depths and material type of underground soil. The classical Hough Transform approach used to reconstruct these hyperbola shapes is computationally expensive, given the large dimensionality of the radargrams. In literature, several approaches propose to first approximate the location of hyperbolas to small segments through a classification stage, before applying the Hough transform over these segments. However, the published classifiers designed for this task present a relatively complex architecture.Aiming at an improved target localization, we propose an alternative classification methodology. The goal is to classify windows of GPR radargrams into two classes (with or without target) using a neural network radial basis function (RBF), designed via a multi-objective genetic algorithm (MOGA). To capture samples’ fine details, high order statistic cumulant features (HOS) were used. Feature selection was performed by MOGA, with an optional prior reduction using a mutual information (MIFS) approach. The obtained results demonstrate improvement of the classification performance when compared with other models designed with the same data and are among the best results available in the literature, albeit the large reduction in classifier complexity.     

Automatic segmentation of color images with transitive closure

In this paper, a mask based automatic segmentation algorithm for color images which uses pixel similarity has been presented. Main concept of the algorithm relies on spatial mask for course segmentation and the Warshall's transitive closure (TC) computation algorithm for region merging. Although the proposed spatial mask approach reduces the computational burden required for segmentation or clustering techniques such as seeded region growing (SRG) or fuzzy c-means (FCM) in which user supplied parameters are essential, it has over segmentation drawback. Therefore, the transitive closure algorithm, which uses adjacency and similarity matrix associated to undirected graph of the over segmented image, has been employed to merge the regions. After comparing to existing methods, the obtained experimental results confirmed that the color images as well as gray level images could be segmented with considerable accuracy. Also computational complexity of image segmentation is significantly reduced. Furthermore, there is no need any user supplied parameter such as the number of clusters or seed points.     

符合FDA 21 CFR Part 11条款的系统搭建与验证

根据FDA21 CFR Part 11条款的规范要求,在色谱仪器综合系统中,建立符合该条款的系统并对其进行验证,并对过程中出现的问题进行总结。使系统达到精确、可靠、持续稳定,具有识别非法记录或被篡改记录的能力。     

Times to breakage versus times for shock wave reflectance in decoupled explosive rock fracturing

Abstract

One result of this research showed the relationship of the crack propagation into the burden as decoupling increased from 1 to 3. The resulting data indicated that the explosive generated gas pressure was the dominate parameter for breaking rock in confined boreholes. The shock energy did not have time to play an effective role in burden breakage, for by the time the stress wave returned to the face, the burden had broken under pressure.     

程序控制流检测算法优化

暴露在太空辐射环境下的星载计算机,其电子元器件可能因受到高能带电粒子的轰击而造成硬件系统的瞬时故障,所以,需要使用容错技术来提高其可靠性。对一种面向硬件瞬时故障的纯软件控制流检测算法RSCFC(Relationship Signatures for Control Flow Checking)进行了有效的改进,通过对标签S进行分段编码,克服了原算法中存在的待加固程序的基本块总数受机器字长限制的问题,并给出了具体的计算证明。计算结果表明,如果机器字长为64位,那么改进后的算法在设定前提下能单层加固程序的最大基本块数可以超过218。与RSCFC相比,改进后的算法在加固基本块总数比较大的程序时,性能开销明显降低而且检错能力保持不变。     

无证书部分盲签名

将部分盲签名和无证书密码体制结合,首次提出了无证书部分盲签名,给出了算法模型,提出了一个具体的方案并对其安全性进行了证明。分析表明,该方案安全性好、效率高。     

短群签名的高效批验证

进入普适通信的时代,从车辆到心脏监听器等大量设备都需要与它们的环境彼此交流信息,从而对验证和安全通信的要求不断上升：①密码费用较低;②能够快速验证大量不同来源的消息;③隐私保护。文章针对一个高效的短群签名体制提出了一个批验证算法,其中验证运算的主要部分只需要2个双线性对,就可满足上面的全部3个要求。     

一种基于数字签名的SSL协议改进策略

针对SSL协议在电子商务应用中存在的身份认证缺陷,提出了一种基于数字签名的SSL协议改进策略,并通过实验证明改进策略的可行性。具体实现上是对SSL协议本身进行改进,增加了对消息的数字签名功能,达到了防抵赖目的,克服了SSL协议的身份认证缺陷。     

非侵入式电力负荷多目标分解框架

现有基于最优化的非侵入式负荷分解方法存在两个问题:使用一到两个特征对家庭负荷的分解效果差;而使用三个及以上特征作为用电设备辨识的目标函数难度高。提出非侵入式电力负荷多目标分解框架,解决传统方法利用特征数少、加权系数难确定等问题。以有功功率、无功功率、视在功率、谐波和电流波形作为电器运行状态的目标函数,建立多目标优化负荷分解模型。利用多目标进化算法(Multi-Objective Evolutionary Algorithm,MOEA)对实测用电数据进行负荷分解求得Pareto最优解集。最后通过多准则决策方法选出识别结果。实验结果表明,增加特征可提高MOEA算法对多个用电设备同时运行时识别准确率,且与当前主流算法相比,所提框架对家庭负荷分解的准确率更高。